September weather forecastDorchester, IL
September
Weather in September
The first month of the autumn, September, is also a moderately hot month in Dorchester, Illinois, with an average temperature ranging between min 59.4°F (15.2°C) and max 77.9°F (25.5°C).Temperature
During September, Dorchester observes a subtle ascent to a still moderately hot 77.9°F (25.5°C) from August's 82.9°F (28.3°C) in the average high-temperature. Dorchester observes an average nighttime temperature of 59.4°F (15.2°C) during September.Humidity
The average relative humidity in September is 75%.Rainfall
In Dorchester, in September, it is raining for 10.4 days, with typically 0.83" (21mm) of accumulated precipitation. Throughout the year, in Dorchester, there are 121.4 rainfall days, and 14.72" (374mm) of precipitation is accumulated.Snowfall
April through October are months without snowfall in Dorchester.Daylight
In Dorchester, the average length of the day in September is 12h and 26min.On the first day of the month, sunrise is at 6:28 am and sunset at 7:29 pm. On the last day of September, sunrise is at 6:55 am and sunset at 6:43 pm CDT.
Sunshine
In September, the average sunshine in Dorchester is 9.3h.UV index
The average daily maximum UV index in September in Dorchester is 5. A UV Index of 3 to 5 symbolizes a medium vulnerability from unsafe exposure to UV radiation for average individuals.Note: A maximum UV index of 5 in September translates into the following recommendations:
Ensure safety - Imperative it is to shield skin and eyes from damage. Given the potency of the midday Sun's UV radiation, one should avoid prolonged exposure. Sun-related eye harm can be minimized with proper sunglasses offering UVA and UVB coverage.
Published by: Weather U.S. | About Us
Data Sources | Weather Forecasting & Climate
Frequently asked questions
Average temperature in September
Dorchester, IL
- Average high temperature in September: 77.9°F
The warmest month (with the highest average high temperature) is July (84.2°F).
The month with the lowest average high temperature is January (35.6°F).
- Average low temperature in September: 59.4°F
The month with the highest average low temperature is July (67.5°F).
The coldest month (with the lowest average low temperature) is January (22.6°F).
Average pressure in September
Dorchester, IL
- Average pressure in September: 30.02"Hg
The month with the highest atmospheric pressure is January (30.16"Hg).
The month with the lowest atmospheric pressure is June (29.92"Hg).
Average wind speed in September
Dorchester, IL
- Average wind speed in September: 6.4mph
The windiest month (with the highest average wind speed) is January (10mph).
The calmest month (with the lowest average wind speed) is July (5.8mph).
Average humidity in September
Dorchester, IL
- Average humidity in September: 75%
The month with the highest relative humidity is July (81%).
The month with the lowest relative humidity is October (71%).
Average rainfall in September
Dorchester, IL
- Average rainfall in September: 0.83"
The wettest month (with the highest rainfall) is June (1.89").
The driest month (with the least rainfall) is February (0.67").
Average rainfall days in September
Dorchester, IL
- Average rainfall days in September: 10.4 days
The month with the highest number of rainy days is July (14 days).
The month with the least rainy days is January (5.8 days).
Average snowfall in September
Dorchester, IL
- Average snowfall in September: 0"
The month with the highest snowfall is December (0.98").
The months with the least snowfall are April, May, June, July, August, September and October (0").
Average snowfall days in September
Dorchester, IL
- Average snowfall days in September: 0 days
The month with the highest number of snowfall days is January (6.3 days).
The months with the least snowfall days are May, June, July, August and September (0 days).
Average daylight in September /
Average sunshine in September
Dorchester, IL
- Average daylight in September: 12h and 24min
The month with the longest days is June (Average daylight: 14h and 54min).
The month with the shortest days is December (Average daylight: 9h and 30min).
- Average sunshine in September: 9h and 18min
The months with the most sunshine are June and July (Average sunshine: 10h and 18min).
The month with the least sunshine is January (Average sunshine: 4h and 24min).
Average sunshine days in September
Dorchester, IL
- Average sunshine days in September: 17.2 days
The month with the most sunshine days is January (20.9 days).
The month with the least sunshine days is July (12.5 days).
Average UV index in September
Dorchester, IL
- Average UV index in September: 5
The months with the highest UV index are June, July and August (UV index 6).
The months with the lowest UV index are January, February, November and December (UV index 2).
Average cloud cover in September
Dorchester, IL
- Average cloud cover in September: 29
The month with the most cloud cover is January (Cloud cover 52).
The months with the least cloud cover are June, July, August and September (Cloud cover 29).
Average visibility in September
Dorchester, IL
- Average visibility in September: 6mi
The months with the highest visibility are January, February, March, April, May, June, July, August, September, October, November and December (6mi).
The months with the lowest visibility are January, February, March, April, May, June, July, August, September, October, November and December (6mi).
